$\forall$$A$, $B$:Realizer.
\\[0ex]R{-}Feasible($A$) $\Rightarrow$ R{-}Feasible($B$) $\Rightarrow$ R{-}interface($A$;$B$) $\Rightarrow$ R{-}interface($B$;$A$) $\Rightarrow$ R{-}icompat($A$;$B$)